Electrical indicating instrument



July 2, 1929. w. c. MccoY ELECTRICAL INDICATYING I1*STRUMl5N'.'L

'2 Sheets-Sheet NBSSSSBS SSSSSMCA Filed June 50, 1927 ATTORNEYS July 2,1929. w, C, MCCOY 1,719,556

ELECTRICAL INDICATING INSTRUMENT Filed June 50, i927 2 Sheets-Sheet 2BIIIII'II ATTORNEYS Patented July' 2, v.1929.

UNITED vSTATES P-ATEFN T OFFICE.

WILLIAIMy C. HCCOY, OF CLEVELAND, OHIO, AS-SIGNOB TO THE TRUST COMPANY,OF CLEVELAND, OHIO, A CORPORATION 0F OHIO.

ELECTRICAL IN DICATIN G INSTRUMENT.

` application nied'mne so, iaz'z. semi no. 202,479.

This inventionrrelates to electrical indicating instruments andparticularly to `an electrically operated instrumentfor indicatingconditions existing at a remote point.

One of the objects of the present invention is to provide an electricalindicating instrument that shall be substantially free from errors dueto residualmagnetism,that shall be inexpensive to manufacture, and thatshall be of rugged construction and reliable in its r operation.

An additional object of the invention is to provide an instrument oftheabove character havin a relatively light -weight armature vane t atconstitutes a damping vane for the instrument.

A further object of the invention is to provide animproved instrumentstructure of inforinsof casings, 'particularly for mounting.

expensive character that shall readily accommodate the mounting thereonof different in instrument panels of automotive vehicles.

An additional object of the invention is to provide an armature carryingvane to which the indicator4 arm is directly secured and from lwhich theindicator arm receives itsposition.

A furtherobject of the invention is to connect the base of theinstrument with the dial l supportingiace solely by the ycore 4 of theactuating coils.

An additional object of the invention is to provide an improved pivotalsupport for an armature of the character herein proposed.

Figure 1 o'f the accompanying drawing is a front or face view of aninsrument embodying the invention.-

' Fig. 2 is a sectional view of the instrument taken substantially onthe line 2-2`of F1g. 1.

Fig. 3 is a cross sectional view of thel 1nstrument shown in Fig. 1taken substantially on line 3--3 thereof.

Fig. 4 is a sectional view','taken substantially on line 4-4 of Fig. 3,of the magnetic parts of the instrument with the energizing' coilremoved. f

Fig. 5 is a view in perspective of the arma.

' a pair of outwardly extending ears 22 and 23 v lture assembly of theinstrument.

the invention. Fi 8 is a side elevational view,- taken sub- "stantiallyon line 8 -8 of Fig. 7, with parts instrument; and

brolren away and shown in the instrument coil.

Fig. 9 is a vcross sectional view of the arma- :section through ture andcoil assembly taken substantially on line 9;-9 of Fig. 10.*.

supporting standards 5 `that are mounted thereon. An outwardlyvextending flange 6 ofthe casing servesto support a correspondmglyflanged bezel 7 in which a suitable crystal 8 is mounted in a springring 9.

Adial plate 10 is conventional manner by magnetic material is secured atone end to the dial plate and serves to support a pair of concentricallyarranged energizing windings 13 mounted on the standards 5by suitablescrews 11. A core 12 of non! and the common terminal 16 of bothwindingsA is connected to terminal post 3. The remaining terminal 17 ofwindingl islgrounded to the dial plate 10.

The 'armature assembly 18 that is shown in enlarged perspective in Fig.5, is mounted within the core 12 of the coil and isA held in place bysuitable screws 19 and 20 that engage the supporting dial 10. Thearmature assembly comprises a U-shaped supporting member 21 ofnon-magnetic material that has formed one on eachleg thereof andapertured 4to receive the securing screws 19 and 20.

Opposite side portions 24 and 25 of the U- shaped support 21 have a pairof ixediron Vanes 26 and 27 mounted thereon that ointly action anarmature 28 of soft iron or-other',

energizations. The armature is preferably of inverted U-shape, beingsecured at its upper end or base portion to the supporting pivot staff'29 by, .suitable collars- '30 vin accordance with conventional practicein repulsion types of electric indicating instruments. The legs of thearmature 28 are disposed at materially different distances from Atheaxisof rotation thereof in order to4 obtain differential repulsioneffects which cause l rotation 'of the indicator hand 31 to differentindicating positions. A suitable pivot bar 32 that has an adjustablepivot bearing 33 is mounted on the armature support 21.

The fixed magnetic vanes 26 and 27 are respectively arrangedsubstantially' at the longitudinal center of their respective enertocontrol the ratio of the currentsowing through ther windings 13 and 14by movement of a suitable contact member 35 alonga resistance unit or byother appropriate mechanism' 1s energized from a source of electricalenergy such for instance as a storage battery 36. l

The windings 13 and 14 are of relatively high resistance suitable'foruse on either alternating or direct current, and a large number of turnsin order that astrong field may be produced. Both windings are -ofsubstan` tially the sainegeneralresistance and magnetizingeiect. Thecumulative effect of the windings on the armature 28 will be to energizethe armature 4to substantially the same .degree for'all 4indicatingpositions of the instrument because the armature extends through both ofthe di'erentially energized windings This greatly reduces the errors of.indications due to residual magnetism in the instrument. I

' The offset, positions 'of the fixed magnetic `vanes 26 and 27 andtheir differential magnetization the respect-ive windings 13 and L 14cause movement-of the varmature to different indicating ositionsbecauseof the repulsion eifectspr uced by' differential energizationl ofthe windings.

The modified form of instrument shown in Fig. 7 to Fig. 12 is of aparticularly inexpensive construction and embodies a4 damping vvane thatalso constitutes the support for the The instrument here shown embodiesa pressed sheet metal base 40 that is proyided with a flange 41 to whichsuitable casings 42 may readil be secured in any conventional manner.incethe entire `instrument lassembly is supported from the base,y agreat variety of'diierent casings may be mounted on av standard form ofinstrument assembly for different uses tov which the instrument may bepllt.

he instrument base has a pair of suitable terminal posts 43 and 44mounted thereon and insulated .therefrom in conventional manner. Thebase member also has a series of ingtongues 45 formed on one end ofthecore 46 of the energizing windings 47 and 48. The

other end of the core Vis secured to the dial -suitable apertures formedtherein for receiv- 'plate 49 in any suitable manner asby welding,

soldering or`by Hanging the end portion of f so the plate. The solenoidwindings 47 and 48 are separated bya suitable plate 50.ix A fixedrepulsion vane 51 of iron or other magnetic material is mounted on' thecore 46 substantlally centrally of the winding 47 anda correspondingrepulsion vane 52 is similarly mounted in cooperative relation-with thewinding 48. The vanes 51 and 5.2 are preferably of soft iron and are oftapered form as shown in Fig. t

l8 and are mounted in opposed relation. The

form of circumferential extentof the repul-` sionvanes may be changed inorder. to get different deflections and scale calibrations for theinstrument that are formed on a suitable dial 53 that is carried b thedial plate 491 and is shown particularlyin Fig. and Fi 12. Thesupporting r prefera ly formed of brass or other non.-

ma netie material having a body'portion of V-s aped -section providsides. The lower end. of the bracket is closed by a base portion 55 thathas a suitable aperture therein for supporting a pivot mounting 56 forone end of the armature. The upper end ofthe body'- portion has a pairof oppositely extending arms 57 bymeans of which the assembly issupported from the dial plate -49 of the instrument. A suitable pivotbracket 58 that is secured tothe arms 57. olf' the sup ort bysuitablescrews 59fcarries an adjusta le pivot bearing 60 for the upper end ofthe pivot staff-61. The bracket-5 4 is cut away suiiiciently to permitan indicator arm 62. that-is carried by the pivot staff to extend overthe indexed dial plate.

By reason of the close fit of the armature The armature assem ly isseparately removable from the remainder of the structure 10, Fig. 11acket 54 is ed with 'divergent vane, that isdesired, in the 4core forthe coil which also provides a dampingchamber and in order to providea'readily aligned and rigid support for the armature, the lower pivotmember 56 extends throu h the end portion y55 of the bracket asuliicient distance. -to be received in -a suitable a erture 63. that isformed in the instrument ase 41.

The armature comprises -a bar 64 of magneticmaterial such as either softor. permanentl magnetized iron that is carried by a suita le armaturesupporting vane 65. The

vane 65 may be formed of thin non-magnetic sheet metal such a's aluminumalloy or from a thin sheet of bakelized fabric or other suitable Vlightweight material.` A non-metallic support and' -zr `soft iron bar aredesirable if the instrument is to be used lon alternating current. j

One edge portion of the sheet material. is suitably folded over the bar64 to securely hold i't in place and the other'edgepor-f tion is foldedaround the pivot stad .61. A. pair of metal collars 66 that tightly litthe' l pivot staff 461 serve to rigidly hold the arma!" 4,

vfixed vanes of magnetic material ture vane in position on the pivotstaff. This construction may be used with or without theparticular formof indicator arm shown and in any otherforms ofrepulsion meters.

The indicator arm particularly comprises an enlarged portion 67 through'which the pivot staff extends and a pairA of foldable. side portions 68that extend therebeyond an'd are adapted to be folded down over theupper edgeof thearmature vane to align the indicator vane with thearmature.

The operation of this form of indicator is substantially the same as thepreceding instrument except that the armature vane constitutes a dampingvane that operates within the enclosed chamber of the solenoid core aswill be well understood by those skilled in the art. A c 'over' member69 that is' glued or otherwise secured to the instrument face serves`,to substantially close the damping chamber. j

The solenoid windings lare, in each case, so wound as to produceconcentric, co-axial fields of the same polarity. Although a controlsystem of the character illustrated is desired'ifor use witheitlier'instrument, any

. used without departin 'from the invention.

`other suitable control system could also be It willrreadily be unerstood that either of i the inst'riinients of the aboverdescribedcharacter will be rugged, inexpensiveto manufacture, and'particularlysuitable for use as fuel level indicators on automotive vehicles and thelike.

WhatIclaimis: 'w

Anf electrical indicating instrument comprising 'a pair ofconcentrically arranged magnetizing windings, a `pair of fixed mag#netic varies laterallyI and longitudinally offset from each otherrelative to 'the axis of said windings and arranged within, thewindings, means operable to vary thev ratio ofthe curj rents through thewindings to differentially 'ofsaid vane is clamped.

vm'agnetize the' vanes, an armatureiextending well into bot-h coils andenergized in accordance with the accumulative magnetizing effectA ofboth windings whereby said armature fis moved to a multiplicity ofindicating positions by windings.

2. An indicating instrument comprising a. pivotally mounted unrestrictedarmature the relative energization of said having a portion ofmagnetizable material disposed substantially parallel to' the axisthereof and unsymmetrical relative thereto, a pair of laterally andlongitudinally offset isposed alongside the armature and atsubstantially the same radial distance from the rotational axis of thearmature, windingsfor differentially energizing the respective ixedmagnetic varies to eiiect indicating movement of the armature to amultiplicity of indicating positions. A

3. An electrical indicating instrument comprising a pivot staii', anonmagnetic vane in the form of a plate of non-magnetic material havingits inner edgeattached to thec staff, an armature of magnetic materialcarried by said vane, a sector shaped damping x chamber wherein saidvane is adapted to opl erate having an arcuate wall in close proximity.to the outer edge of said vane, and ener.--

gizing means for controlling movement of the armature, whereby said vaneconstitutes a non-magnetic support for the armature and a damping devicefor the instrument.

4. An electrical indicating instrument comprising a pivot staff, anarmature carrying vane comprising aplate having its inner edge securedto said sta', andan indicator proJecting radially from said staii' andhaving folded portions'betweenwhich a portion A 5. Ah electricalindicating -instrument comprising apivot staf, an armature carry-iA ingvane comprising a plate .having its inner edge portion encirclingtlie'pivot stad, and an indicator carried .by said staff at one end ofsaid vane, said indicatdr projecting radiallyv from the staffv andhaving foldedportions between which a portion. of vsaid vane is clamped,anda securing-collar on said staii at each end portion thereof betweenwhich the WILLIAM o. MeCoY.

